The invention relates to an excavator for underwater ordnance. It is established that inspection of underwater ordnance is very difficult, time consuming and dangerous. Ordnance inspection and disarming is even more complicated and involved when the ordnance is fully or partly buried either intentionally or due to the natural forces of the sea. In order to inspect buried or covered ordnance it must first be uncovered.
The very nature of the ordnance may make excavation extremely hazardous. The ordnance may be both magnetically and acoustically influenced, and possibly impact and attitude sensitive. Ideally, the excavation procedure should be accomplished either automatically or by remote control to minimize the risk to the divers. Such unmanned operation is complicated by the various possible shapes of the objects, which may include artillery projectiles, mines, and torpedoes. It is further complicated by the natural tendency of typical sea floor materials to flow back into the excavation site. To avoid the need to excavate a large, shallow hole, an external barrier or cofferdam is required. This reduces the amount of material to be excavated by increasing the effective angle of repose of the sides of the hole.
The various shapes of the covered ordnance that may be encountered necessitates the use of excavation equipment and techniques which will effectively uncover a variety of rectilinear shapes, including rectangular or other unusual shapes. Because of these factors the excavating system should have means for circumscribing the region that is to be cleared or uncovered.
Therefore, the field of the invention is an underwater excavator with means for circumscribing buried-underwater ordnance.